Generally, a delay circuit is widely used for delaying an input signal for a specified time interval, thereby generating an output signal. For example, after a pulse signal is inputted into the delay circuit, a delayed pulse signal is outputted from the delay circuit after the specified time interval.
However, if the pulse width of the pulse signal is very narrow (i.e. smaller than the specified time interval), the waveform of the delayed pulse signal from the delay circuit is suffered from serious distortion.
FIG. 1 is a schematic functional diagram illustrating a conventional pulse delay circuit. As shown in FIG. 1, the conventional pulse delay circuit 100 comprises a rising trigger 102, a first delay unit 104, a falling trigger 106, and a second delay unit 108.
An input pulse signal Pin is received by the rising trigger 102 and the falling trigger 106. The rising trigger 102 generates a first triggering signal Tr at a rising edge of the input pulse signal Pin. Moreover, the first triggering signal Tr is transmitted to the first delay unit 104. The falling trigger 106 generates a second triggering signal Tf at a falling edge of the input pulse signal Pin. Moreover, the second triggering signal Tf is transmitted to the second delay unit 108.
After the first triggering signal Tr is delayed for a specified time interval by the first delay unit 104 and the second triggering signal Tf is delayed for the specified time interval by the second delay unit 108, the delayed first triggering signal Tr and the delayed second triggering signal Tf are combined as a delayed pulse signal Pout.
FIG. 2 is a schematic functional diagram illustrating another conventional pulse delay circuit. As shown in FIG. 2, the conventional pulse delay circuit 200 comprises a delay unit 202 and a monostable multivibrator 204. After an input signal Pin is received by the delay unit 202, a delayed input signal Pin_d is generated. After the delayed input signal Pin_d is received by the monostable multivibrator 204, a delayed pulse signal Pout is generated.
Generally, the waveform of the delayed input signal Pin_d may be suffered from distortion. Moreover, after the monostable multivibrator 204 is triggered by the delayed input signal Pin_d, the waveform of the delayed pulse signal Pout from the monostable multivibrator 204 is no longer suffered from distortion.
However, since the circuitry of the monostable multivibrator 204 is very complicated, the layout size of the monostable multivibrator 204 in the integrated circuit design is very large.